This invention relates generally to real time telephone conferencing with a group of participants, and more particularly to new and convenient methods of selecting a specific, customized group of participants for a particular conference from a set of one or more previously defined and existing groups. The pre-defined groups could be personally defined groups (e.g., a group of business associates or relatives of the user); alternatively the groups could be defined by some other entity, such as the user's employer.
In current practice, a user of a client station, e.g., a mobile phone or other station, can initiate a real-time media session with a group of one or more parties with the aid of a conference server. A widely known and used protocol enabling this communication is the Session Initiation Protocol (SIP), reflected in Internet Engineering Task Force RFC 3261, the contents of which are incorporated by reference herein. Other protocols could be used, including modifications to the Simple Mail Transfer Protocol (SMTP).
Generally speaking, the process of initiating such a session involves the initiating user selecting a conference group (also known as a Push-to-Talk (PTT) or “buddy” group) from a menu or listing on the user's station and directing the initiating station to initiate the session. The user's station could be a cellular telephone or other telephone device equipped with real time conferencing software. The initiating station would then send an invitation message (such as SIP INVITE message) to a SIP conference server, requesting initiation of the session with the members of the conference group. The initiation request provides a group-identifier, which the conference server translates into a list of group members, by reference to a group database. The conference server then (i) engages in additional signaling with the initiating station to establish a real-time media session, e.g., an RTP session, with the initiating station; (ii) engages in signaling with each participant station in the conference group to establish a real-time media session with each participant station, and (iii) bridges the sessions together to allow the parties to communicate with each other. In some instances, the bridged communication is a half-duplex mode in which just one party can “have the floor” and speak at a time without clipping or over-riding other speakers. Conventional SIP signaling is used to set up each conference leg.
In current practice, there is no way to de-select a few (e.g., one or two) members from the conference group list for a particular session, without permanently deleting them from the group. In other words, if the user does not want to include an entire pre-selected group, but rather the entire group minus one person, they would have to individually select and enter the persons they wish to join into the conference. This process becomes quite cumbersome if the group is a large one. The art has lacked a more flexible method for customized grouping of conference participants.